textproduct: Rapid City

KEY MESSAGES

- Very windy conditions behind a cold front for Thursday - Critical fire weather conditions through early this evening for parts of northeastern WY/southwestern SD. Near critical fire weather conditions Friday. - Unsettled weather through the weekend per a series of fronts with up/down temperatures trending coolish for the weekend.

DISCUSSION

(This Evening Through Wednesday) Issued at 1228 PM MDT Wed Jun 10 2026

18z surface analysis had weak high over the CWA. 0.5km visible satellite loop had CU field starting to increase in size per daytime heating/weak buoyancy. Might see a few shra/TS during peak heating this afternoon/early evening. Water vapour loop had mean upper trough over central Canada, extending into the northern Plains. Distinct shortwave trough rotating southeast into MT per water vapour, which is the main forecast concern.

Shortwave trough whips through the northern plains overnight into Thursday morning pushing a cold front through the CWA. Decent QG- forcing should assist shra/isolated TS moving across the area. Isallobaric forcing modest, but it will be accompanied by steep low-level lapse rates and good subsidence for Thursday which should tap into 25-40kt mixed boundary layer. Showers could enhance. NBM looks rather strong for peak wind gusts (~60mph) given forecast Bufkit momentum transfer. Have shaved some speed from prescribed forecast wind elements. Still, very good chances (50-90% chance >45mph gusts) for Wind Advisory gusts behind the cold front for the usual areas from K2WX-KRAP and far southwestern SD. ECMWF EFI guidance paints 80th percentile wind gusts with a shift of tails contour. Temperatures will be near guidance.

Rest of the forecast looks unsettled as a series of disturbances traverse the northern plains per northwest flow aloft. Deeper trough brings PoPs/cooler temperatures for the weekend. Each front/disturbance will bring gusty winds. There are hints that an upper ridge may develop for the middle of next week, but increasing ensemble spreads portend lower confidence.

AVIATION

(For the 18Z TAFS Through 18Z Thursday) Issued At 1138 AM MDT Wed Jun 10 2026

Mostly VFR conditions are expected through the forecast period.

Gusty northwest winds will persist much of today, diminishing a bit in the evening, but picking back up overnight. Isolated light showers may be possible this afternoon and evening, and brief MVFR conditions may be possible, but generally expect VFR even in showers/storms. Early Thursday morning, MVFR/IFR cigs move into northeastern WY and the northern Black Hills, and are expected to impact KGCC.

FIRE WEATHER

Issued At 1228 PM MDT Wed Jun 10 2026

Critical fire weather conditions (west winds 20-30g45 MPH, MinRH ~11%) will persist into early this evening with a Red Flag Warning for parts of northeastern WY/southwestern SD. The rest of the week will be unsettled as a series of fronts move through, each containing gusty winds and variable temperatures. Elevated to near-critical fire weather conditions are expected Friday due to very dry air (teens minimum relative humidity over northeastern Wyoming and southwestern South Dakota).

UNR WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory from 3 AM to 5 PM MDT Thursday for SDZ001-002-012- 013-027-031-041-072-073-075-078. Red Flag Warning until 8 PM MDT this evening for SDZ322-326. WY...Red Flag Warning until 8 PM MDT this evening for WYZ315-317.